Interesting to see that over there you have black deer. In my area black roe deer is quite common. The following page I am not affiliated with will show you some examples:
http://www.iberhunts.com/en/Programas/1-alemania-caza-de-corzos-negros/The color variant was created by mutation in the form of excessive black pigment deposits. We are talking about melanism, which we also find more frequently in fallow deer and rabbits. The most famous blacks are the black panthers. In evolutionary theory we also talk about variability. The opposite of this is albinism, in which pigment deposits are completely absent.
